Assessment of endothelial glycocalyx degradation in sepsis using direct visualization with sublingual microscopy

The endothelial glycocalyx plays a crucial role in the pathophysiology of sepsis, but assessment of glycocalyx injury in clinical settings remains challenging. Perfused boundary region (PBR) is derived from sublingual intravital video microscopy and has been studied as a surrogate of endothelial glycocalyx barrier function. The goal of this study was to determine whether PBR is associated with circulating heparan sulfate (a biochemical marker of glycocalyx degradation), sepsis status, in-hospital mortality, and intravenous (IV) fluid administration.

This was an ancillary study to the randomized clinical trial Protocol-Based Care for Early Septic Shock (ProCESS). The patients were enrolled from six hospitals and controls from two hospitals. Subjects underwent sublingual microscopy. We assessed the association between PBR and heparan sulfate levels. We also compared the baseline PBR between sepsis and non-infected controls, and between the survivors and non-survivors. Lastly, the association between IV fluid administration and PBR was assessed using a linear mixed-effects model.

A total of 193 subjects were included: 144 had septic shock and the in-hospital mortality rate was 12.5%. The PBR was associated with levels of circulating heparan sulfate (r = 0.32, R² = 0.10, p = 0.02). The baseline PBR was higher in sepsis compared to controls (2.29 ± 0.40 vs. 2.02 ± 0.41, p < 0.01) but not different between survivors and non-survivors. PBR was also not associated with IV fluid administration volume.

Findings suggest a link between PBR and endothelial glycocalyx degradation observed in sepsis.